Beer making has been practiced for many years. Sugars are extracted from malted grains through a process called mashing. The sugars are boiled with hops, and the resultant wort is fermented with yeast. There are many styles of beers, each of which has is its particular character.
The sugars that are extracted from the malted grains can be changed by varying temperature and time of the extraction. The temperature and time profile may include raising and lowering the temperature, including holding the grain and liquid mash at a specific temperature for a defined period of time. The accuracy of the mashing process defines how repeatable a beer can be made from one batch to another.